Dirigible airship



A. K. MATTULLATH.

DIRIGIBLE AIHSHIP.

APPLICATION man APR. 1o, 191g.

Patented May 3, 1921.

/m/EA/m:

Mv AHORA/Ew'.

UNITED STATES PATENT OFFICE. l

.ALICE IK. MATTULLATH, OF INWOOIJ, NEW YORK, ASSIGN OR T0 AMERICAN BALSA CORPORATION, OF NEWvYORK, N. Y., A CORPORATION OF NEW' YORK.

DIRIGIBLE AIRSHIP.

Specification of Letters Patent.

Patented Mays, 1921.

Application led April 10, 1918. Serial No. 227,632.

To all whom it may concern Be it known that I, ALICE K. MATTUL- LATH, a citizen of the United States, residing in Inwood, county of Nassau, and State of New York, have invented certain new and useful Improvements i`n Dirigible Airships, of which the following is a specification.

This invention relates to dirigible airships of the rigid type and has for its objects the production of'an airship in which the outer envelop consists essentially of a non-metallic, substantially rigid, non-splintering, cellular, heat-insulating medium. possessing considerable strength and elasticity an withal being waterproof, extremely light and buoyant in water.

I am aware that heretofore aluminum envelops have been proposed which were provided with numerous compartments adapted to contain ballonnets, c'. e., small balloons which were filled to the desired pressure with hydrogen or other suitable gas. Obviously, the object of such sub-division was to prevent the collapse of the entire structure if a portion of the envelop and one or more compartments were destroyed by shell or rifle fire, or from collision or otherwise. While such a type of dirigible has man advantages, it also has certain decided isadvantages which it is the object of this invention to eradicate. Chief among these objections is the high co-eiciency of heat trans-- mission of aluminum, it being, as is well known, an excellent conductor of heat. Accordingly, as a dirigible having anv aluminum envelop passes from lower to higher altitudes or vice versn, there is a corresponding shrinkage or expansion of the gas field with a consequent variation of the buoyancy. Furthermore, in the event of the exhaustion of the as, such a dirigible is so heavy as to sink wen a landing upon water is necessitated. These and many other objections are overcome by my improved dirigible which is fully set forth and described in the accompanying specification and drawings formin a part thereof, in whichigure l is a longitudinal elevation of my improved dirigib'le, a portion being shown in section;

Fig. 2 is a transverse section along the line 2-2 of Fig. l;

Fig. 3 is an enlarged detail fragmentary section of the outer envelop showing the bracing therefor.

above the car.

Referring to the drawings and the construction shown therein, the reference numeral l designates the outer, rigld, sectional envelop of artificially preserved and waterbolted to a skeleton angle iron frame as hereinafter described. The dirigible is provided with one or more cars, as designated by the numeral 2, which are adapted to contain the power plant, including propelling mechanism, as well as the necessary fuel, ballast, crew, radio-apparatus, etc. It is also equipped with one orA more, vertical rudders 3, vertical fins 4, 4', and horizontal fins 5, 5, elevating devices 6 (the one on the opposite side not being shown) all of which are customary and well known in the art and not specifically claimed herein.

The entire envelop is preferably sub-divided by radial, longitudinal partitions 8, 8 and 9, l0, 10 into sub-compartments a, b, c, d and e. Two transverse vertical partitions 7, 7', preferably also of balsa wood, form a central compartment immediatel The latter' compartment 1s provided with a floorof any suitable flooring material 11, which is provided with suitable trap door or othermeans of access (not shown). The said subfdivision of t e en-` velop bythe radial partitions insures against the destruction of thedirigible in the event a portion of the envelop is destroyed byshell fire or otherwise, since each compartment will contain a separate gas-eld that is adapted -to be supplied with hydrogen through a supply pipe (not shown) common to all the indlvidual compartments. Such pipe is provided with valves (not shown) for pre-venting the escape of the gas from any single compartment in the event of destruction of the adjacent compartment, provided of course also such compartments remain intact. However, such sub-division of the envelop into compartments forms no part of my invention.

Each of the compartments into which the envelop is divided is preferably provided with separate ballonnets made of fabric commonly known as balloon-cloth, although if the joints between the balsa wood sections of the outer envelop are lined with a cementitious coating capable of rendering the entire inner surface and joints gas tight, the outer envelop itself Will be sufficiently impervious to permit of the balloon-cloth ballonnets being dispensed with, and in such cases the gas in each compartment contacts directly with the lining of the outer balsa Wood envelop. Owing to the great strains to which dirigibles are subjected, I preferably, as aforesaid, however employ balloon cloth vballonnets in each compartment, filling the same in the customary manner from a central generating station.

Balsa wood (Ochroma Zagopus), which is the material from which I preferably construct the outer envelop of the dirigible, grows extensively in Costa Rica and other entral and northern South American States as a second-growth tree. It has a S. G. of about .25 and is believed to be the lightest wood that is commercially used. It is composed of very thin-walled cells, which are barrel-shaped, interlace With each other, and are almost devoid of Woody fiber. These cells are filled with air, making a natural structure Well adapted to prevent the transmission of heat, because of the particles of air imprisoned in the material Without interconnecting fibers. Unless encysted .or otherwise treated With a suitable preservative its life under ordinary conditions is extremely short. The ordinary commercial balsa Wood which is seldom perfectly dry Weighs between 8 and 13 lbs. per cubic foot, when thoroughly dried but 7.3 lbs. per cubic foot, whereas Missouri cork wood, one of the lightest varieties of cork, Weighs approximately 18.1 lbs. per cubic foot.

Said balsa Wood is also remarkably `free from Woody fibers'.- It` is extremely elastic in so far as .recovery against transverse' deformationis concerned. 1t is unusually strong,

its crushing `strength approximating onehalf that of White pine'or spruce." Further-- more, it isalmost impossible to split or splinter the Wood byI -driving nails or'shooting bullets through it. "Itlalso has-anextremely loW-efiicient of heat'transmission,`

1 for example, as tested'by the BureauL of mitted through balsa Wood per inch of thickf ness is 5.98 or inother Words l'5.98-flritish besides preventing the bad effects of dry rot which often accompanies supercial treatment of Wood of this type. In such treatment the Water normally present in the Wood is driven off, the Wood is made Waterproof, its quality of being readily Worked with tools is greatly improved and its Weight is not materially increased since the added paraffin replaces principally the Water which has been driven off. Such Waterproofing which is described in detail in the Patents to R. A. Marr, No. 1,121,644 of December 22, 1914 and Reissue No. 13,952 of July 27th, 1915, and constitutes no part of my invention, as herein set forth, is especially adapted for the treatment of balsa Wood intended for the construction of the herein ldescribed envelop. Such envelop may be further strengthened, if desired, by covering the outer surface, or if 'desired both the outer and inner surface, With a Waterproof skin of tough paper, canvas, or other suitable textile material so as to forma smooth continuous vhard shell, thereby lessening the air-resistance of the envelop, as Well as making it possible to dispense entirely with a lining of balloon cloth or with individual ballonnets confined in the separate compartments. Such coverings for both the inner and outer surfaces are specifically shown in F ig. 3 and are indicated by the reference characters 12 and 13 respectively.

Having thus described my invention, What I claim and desire to secure by Letters Patent is 1. A substantially gas-tight gas envelop for containing the'main buoyant gas field' ofv 'specificigra'vity',\ the pores"'of"whic`h'have been lined or'encystedthroughout by asuitvablev preservative and Waterproofing 4"maiterial, whereby'a Tgas envelop' is provided havingl extreme' lightness, a high degree of buoyancy in'vvater, durability, and highheat l @insulating and non-splinterable properties. Standards, the co-eiiicient of' heat trans- 2L substantially .gas-tight gas' envelop for/.containing the main buoyantv gas field 'of'dirigible' airsh'ips comprising a skeletonframef'embodying a' relatively hard and tough material, and Walls which are principally composed'of balsa Wood having lits pores lined or encysted throughout by a suitable preservative a-nd Waterproofing material.

3. A substantially gas-tight gas envelop for containing the main buoyant gas field of dirigible airships' comprising a shell having a skeleton-frame embodying a relativelyy hard and tough material and having its Walls principally composed of balsa Wood pieces Whichhave been treated to -cause the pores thereof to be lined or encysted throughout by a suitable preservative and Waterproofing material, and which balsa wood pieces are suitably joined together and reinforced by a suitable adherent surface covering to form a continuous surface.

4. A substantially gas-tight gas envelop for containing the main buoyant gas field of dirigible ail-ships, comprising a shell having a skeleton-frame embodying a relatively hard and tough material, and having itsv Walls principally composed of balsa Wood pieces which have been treatedl to cause the pores thereof to be lined or encysted throughout by a suitable 'preservative and waterproofing material, and which balsa Wood pieces are suitably joined together and reinforced by a tough adherent outer covering and havingl an inside lining of a suit` able gas-proof material.

In Witness whereof, I have hereunto set my hand at New York, county and State of New York, this 4th day of pril, 1918.

- ALICE K. MATTULLATH. 

